Ionization system for gaseous conduction lamps



July 4, 1950 R, BECK 2,513,396

IONIZATION SYSTEM FOR GASEOUS CONDUCTION LAMPS Filed July 22, 1946 J/YVE/VTO? firroemsn Patented July 4, 195

IONIZATION SYSTEM FOR GASEOUS CONDUCTION LAMPS Robert 0. Beck, Los Angeles, Calif., assignor of one-half to Wilcox Photo Sales, Los Angeles,

Calif., a partnership Application July 22, 1946, Serial No. 685,409

13 Claims. (01. 315'-241) My invention relates generally to gaseous discharge lamps, and more particularly to ionization systems adapted to initiate the discharge of such a lamp so that the timing of the flash of light emitted thereby may be accurately controlled.

In recent years, considerable progress has been made in the field of so-called flash photography by the use of gaseous conduction lamps which are adapted to emit an extremely intense light for a very short time. The power to operate such lamps has generally been derived from a capacitor which is permitted to discharge through the lamp, and the light is extinguished when the capacitor has been discharged, which usually occurs in a matter of comparatively few micro-seconds.

In one form of gaseous conduction lamps, a suitable gas under a relatively low pressure is used as a conducting medium; and the application of the relatively high voltage across the terminals of the lamp causes a sufficient ionization ofthe gas contained therein to establish a current flow which produces the desired illumination. However, while such lamps may be designed to produce a relatively large amount of illumination, an even greater amount of light may be secured by increasing the pressure of the gas within the lamp. When this is done, however, the gas is no longer capable of being ionized by the application of any voltage within safe'practical limits, andv other ionizing means must be provided. One method of ionizing the gas which has been successfully used is to provide a trigger or trip wire electrode around a portion of the outside of the glass envelope containing the gas.

the electrodes of the gaseous conducting lamp,

Another object of my invention is to provide sucha system wherein the conductors which extend from the power supply to the lamp are reduced to a minimum, and none of the conductors minal 26 and conductor22.

is energized until the instant the lamp is to be lighted.

It is a further object of my invention to provide such a system in which the tripping or ioniziation of the gas is both certain and instantaneous.

Still another object of my invention is to provide an ionization system making use of standard parts and capable of being mounted in a very small space, generally within the reflector of the lamp itself.

In addition, itis another object of my invention to provide a device which furnishes a simple, ready and positive means of determining whether or not the main capacitor has been charged to the proper voltage to operate the lamp.

It is a still further object of my invention to provide such devices which are simple and economical to build, and which will provide trouble-free service over an extended period of time.

These and other objects and advantages of my invention will become apparent from the following description of two forms thereof, and from the drawings illustrating those forms in which:

Fig. 1 is a schematic wiring diagram of a lighting system built in accordance with the first form of my invention wherein an impulse or unidirectional surge is used to trigger the gaseous conduction lamp; and

Fig. 2 is a schematic diagram of a fragment of a system similar to Fig. 1, built in accordance with the second form of my invention wherein an oscillatory surge is used to trigger the gaseous conductionlamp.

Referring now to the drawings and particularly to Fig. 1 thereof, the numeral [0 indicates a power transformer having a primary winding II which may be connected to any suitable source of alternating current (not shown), and having a plurality of secondary windings l2 and I3, one winding l2, providing a relatively low voltage, and the other winding, l3, producing a relatively high voltage. Secondary winding I2 is provided with terminals M and [5 of which terminal [4 is connected by a conductor It to a terminal ll of a filament or heater 20 of a rectifier tube 2|. Terminal I5 is connectedv by conductors 22 and 23 to the other terminal 2d of filament 20, and the latter is therefore energized from'the secondary winding l2. The high voltage secondary winding I3 is provided with terminal 25 and 26 of which terminal 25 is connected by conductor 2i to the anode 28 of the tube 2| and a half wave rectified current therefore appears between ter- It will be apparent 3 that if desired, a full wave rectified current could be provided by making a few simple changes well known to those skilled in the art. However, this is not necessary and adds to the cost of the equipment.

The direct or pulsating current appearing between terminal 26 and conductor 22 is used 'to charge a capacitor 30 which may later be discharged through a gaseous conduction lamp. One of the features of my system is that it may be used to discharge one or more gaseous conduction lamps simultaneously; but the power drawn by the primary winding II is proportional to the number of lamps which are to be lighted, instead of being a constant. These features are secured by providing a separate discharge capacitor, such as capacitor 30, for each gaseou conduction lamp which is to be lighted, and charging only those capacitors to which lamps are connected. In this way, the difficulties attendant upon discharging a si le capacitor through a plurality of gaseous conduction lamps in parallel, is avoided.

As shown in Fig. 1, I secure these results by connecting a resistor 3! between conductor 22 and a socket member 32 of a separable plug connector 33. The separable plug connector 33 is shown as having three conductors; and plug 34, which is adapted to fit into socket 32, is connected by a conductor 35 to a second plug 36 which fits into a corresponding socket 31. Socket 3i is connected by conductor 38 to one terminal 4 of capacitor 30, whose other terminal M is connected by means hereinafter described to terminal 26 of secondary winding I3.

From the foregoing it will be seen that a circuit from conductor 22, through resistor 3|, to capacitor 30 and thence to terminal 26 is completed only'when the two portions of the separable connector 33 are engaged. The connector 33 thus'acts as a switching means to connect or disconnect the capacitor 30 from the charging circuit, the resistor 3| being included in the charging circuit to act as a current limiting device in a manner well known in the art.

From terminal 4| of capacitor 30, connection is made-by'conductor 42 to terminal 43 of a movable contact 44 of a relay 45. The relay 45 is provided with an operating coil 46 which is connected by conductors 49 to a suitable control circuit (not shown) of any convenient type, of which there are many known in the art. When coil 46 is deenergized, movable contact 44 bears against a fixed contact 41 which is connected by a conductor 48 to terminal 26.

The charging circuit for capacitor 30 may now be traced from terminal 26 through conductor 48, contacts 44 and 41, terminal 43, conductor 42 and through conductor 38 to socket 31. From socket 31, connection is made through plugs 34 and 36 and conductor 35 to socket 32, and then through resistor 3I, conductors 22 and 23, filament 20, anode 28, conductor 21, to terminal 25 and then through secondary winding I3 to terminal 26. A resistance-capacitor circuit similar in all respects to that just described is connected in parallel with the previously described circuit to conductors 22 and 48, and the elements thereof are given similar numerals with an a added thereto. The separable connector 33a may thus be used to connect another gaseous conduction lamp, and when this is done, capacitor 30a is charged at the same time that capacitor 30 is charged.

To indicate when capacitor 30 is charged to a voltage sufficient to operatethe lamp 56, I have 4 developed the indicating system shown herein, which includes a glow lamp IOI which flashes when the proper value is reached. It would be a simple matter to connect the glow lamp IOI so that it glowed continuously when the capacitor is charged to the proper voltage; but a continuous glow is not so satisfactory as a flashing light for a number of reasons. One'of the principal advantages of a flashing light is that it is easier to see than a continuous light, and it is not necessary to look directly at the light in order to determine if it is lighted. Furthermore, a flashing light is less likely to be confused with a reflection from the. glass envelope enclosing the electrodes, and the intensity of the individual flashes is brighter than a continuous glow.

I secure these advantages and provide a flashing indicator by connecting a voltage divider across the capacitor 30 and connecting a modified form of relaxation oscillator to the voltage divider. As shown in Fig. l, the voltage divider includes resistors I02 and I03, connected in series with each other by conductor I04, and with the ends of the series circuit connected to conductors 38 and 42. Between conductors 38 and I04, and in parallel with resistor I03, I connect a modified form of relaxation oscillator comprising the glow lamp I02 which is connected in series with a parallel circuit including capacitor I05 and resistor 505. This differs from the usual relaxation oscillator in which the capacitor is connected in terminals.

parallel with the glow lamp, the other connections remaining the same. Operation of this circuit is also modified from that of the customary q relaxation oscillator since capacitor I05 does not build up a charge which it then discharges through glow lamp IOI. Instead, as the voltage on capacitor 30 increases, the voltage between conductors 38 and 42 increases, and consequently the voltage between conductors 38 and I04 increases. Since the current drawn by a glow lamp is negligible before ionization takes place and the lamp starts to glow, substantially no current flows through resistor I06 to produce a voltage drop, and hence the full voltage appearing between conductors 30 and I04 will be applied to the terminals of the lamp IOI. When this voltage equals the breakdown or striking voltage of the lamp, the lamp is momentarily lighted.

When lamp IOI is lighted, the current flow therethrough is no longer negligible, and a voltage drop is then produced across resistor I06. This resistor is of a relatively high value, andthe amount of current which flows through it is sufficient to produce a voltage drop which reduces the potential applied to the terminals of the lamp IN to a value below that necessary to maintain the discharge. Consequently, the glow ceases; but capacitor I05 which is connected to the terminals of resistor I06 has now been charged to the voltage which appeared between those Until this charge is. dissipated, the voltage appearing between conductors 38 and I3 4 cannot be applied to the terminals of lamp IliI. Resistor I06, however, acts as a leak or bleeder resistor to discharge. capacitor I05, and when the latter is discharged, the lamp IOI again flashes and the cycle is repeated. The frequency of the flashes may be varied by varying the resistance of resistor I06, and I have found that if capacitor 05 has a capacity of approximately 0.2

voltage equal to thestriking voltage of lamp IN is obtained between conductors 38 and I04 when a voltage of approximately l750.volts is applied between conductors 38 and 42... By way of example only, and not as a limitation, I have secured satisfactory results when resistor I02 has a value of approximately one megohm, and resistor I03 has a value between 70,000 and 100,000 ohms. I

When operating'coil 46 of relay 45 is energized, movable contact 44 is moved away from contact 41 and completes a circuit through a fixed contact 50. Contact 50 is connected by conductor to a socket 52 of the separable connector 33 with which plug 53 is adapted to cooperate. The volt-' age appearing between terminals 40 and 4| of capacitor 30 thus appears between plugs 36 and 53 respectively of the separable connector 33, and these plugs may be connected by suitable connectors to a gaseous conduction lamp to energize the latter. As shown in Fig. 1, plug 36 is connected by conductors 35 and 54 to terminal 55 of gaseous conduction lamp 56; and plug 53 is connected by conductor 51 to terminal 58 of the same lamp. Terminals 55 and 58 are the terminals of the principal electrodes of the lamp 56, between which the arc is established once the gas contained in the lamp has been ionized. However, as previously mentioned, for certain types of lamps, the voltage applied between terminals 55 and 58 is insufficient to cause this ionization, and an auxiliary triggering means must be used. In the form of lamp described in the Germeshausen patent previously mentioned, this triggering is done by means of an auxiliary electrode wrapped around the outside of the glass envelope enclosing the column of gas it is desired to ionize. When a relatively high potential is applied to the triggering electrode 59, the ionization within the lamp 56 is started, and the capacitor 30' may then discharge through the lamp to produce a brilliant flash of light. Until such time as the trigger electrode 55 is energized,.however, the capacitor 30 will not discharge through the lamp 56 even though the two are connected so as to be, in all other respects, capable of producing such a flash.

Heretofore, the energization of the triggering electrode 60 has been provided by a separate conductor extending from theelectrode to the control circuit and energized at that point through some suitable switch adapted to control the flashing of the lamp 56. I have improved and simplified this control by 'making use of the surge, whether in the nature of a unidirectional impulse or of an oscillatory character, to provide the high voltage necessary for the triggering electrode 59.

In the form shown in Fig. l, the triggering electrode 59 is energized by means of the impulse appearing between conductors 54 and 51 when relay 45 is energized. As is well known in the art, the sudden closing of a circuit produces a voltage rise in that circuit which may have a relatively steep wave front. This rise or change in voltage possesses some of the attributes of an alternating current, and may be transmitted through a capacitor and used to operate a transformer. I therefore provide a capacitor 60 having terminals BI and 62, of which terminal 61 is connected by conductor 63 to conductor 54. Terminal 62 is connected by conductor 64 to the primary winding 65 of a transformer 66. The other terminal of primary 65 is connected by conductor 61 to conductor 5'1; and a series circuit consisting of the capacitor 60 and primary winding 65 is connected in parallel'withthe gaseous conductionlamp 56. Transformer 66 has a secondary" winding 68, of which one terminal is connected by conductor 10 to conductor 51, and the other terminal is connected by conductor ll to the trigger electrode 59. Because of the characteristics of the voltage change applied to the terminals of To use my device in the photographing of objects, transformer 10 is energized by connecting it to a suitable source of power, and, with the relay d5 deenergized, the electron discharge tube 2| will provide direct current to charge capacitors and 30a.

nectors to which gaseous conduction lamps areconnected. Thus, as shown in Fig. 1, capacitor" 30 will be charged but capacitor 3% will not be charged since no connection is made between socket 32a and 31a as is done by conductor 35 and plugs 34 and 36 in the plug half of the separable connector 33.

When capacitor 30 has been charged and it is desired to operate the lamp 56, the operating coil 46 of relay is energized in any suitable manner, and capacitor 30 is thereupon disconnected from the charging circuit and connected to the lamp circuit by the operation of the movable contact 44 of the relay.

When capacitor 30 is connected through the relay 45 and separable connector 33 to conductors 54 and 57, the voltage between those conductors rises rapidly, as does the voltage between terminals 55 and 58 of lamp 55. However, as previously mentioned, this alone is insufficient to cause the ionization of the lamp necessary for its operation. This rapid rise in voltage, though, is transmitted through capacitor 65 and impressed across the terminals of primary 65 of transformer '65. The sudden energization of primary 65 causes lines of force to be formed which induce a relatively high voltage in the secondary winding 68 0f the transformer; and this voltage is applied to the triggering electrode 59 to start the ionization of the gas within lamp 56 so that the latter may provide the desired flash of light. The capacitor 60 must be capable of withstanding the steady state voltage appearing between conductors 54 and 57 so that the charge of capacitor 3!] will not cause the dielectric of capacitor 66 to break down and permit capacitor 30 to discharge through it, and transformer 66 must have a turn ratio between the primary and the secondary 68 so that a suflicient voltage is provided to energize the triggering electrode 55. By Way of example only, and not as a limitation, I have found that if capacitor 60 has a capacity of .25 to 1.0 mid, transformer 66 has a turns ratio of 300 to l and capacitor 30 has a capacity of 28. mid, very satisfactory results are obtained when the latter is charged to a voltage of 1750 volts. I I

When capacitor 35 is connected to conductors 54 and. 5?, capacitor 60 is charged and a voltage is impressed across the terminals of the primary winding 55 of transformer 66. Even though the latter voltage is only transient and is not of an oscillatory nature, it causes a sudden change in thelines of force linking the primary and secondary windings 65 and 68 respectively, and causes a'relatively high voltage to appear between'the' However, only those capacitors will be charged which are connected to separable con-- noted that only a momentary surge of power goes through the primary winding 65, since once the capacitor 50 has been charged, there is no further passage of current through it.

It will thus be seen that by making use of the impulse which appears between conductors v54 and when capacitor 50 .is connected thereto,

the gaseous conduction lamp 55 may be lighted without requiring a third or triggering connection to the trigger electrode 59 in order to initiate the discharge.

Description of Fig. 2

In the form shown in Figure 2, the connections of the various members to the sockets 32, 31, and 52 of the separable connector 53 are identical with the connections previously described. Thus, capacitor 30 may be charged through resistor 3| when the movable contact 44 of relay :35 is against fixed contact 41 to complete the circuit from conductor 22 to conductor 48. From plugs 53 and 34 of the separable connector 53, conductors 54 and 5! respectively are connected to terminals55 and 58 of the gaseous conduction lamp 55, all as in my previously described form. The lamp 56 is provided with a trigger electrode 59, but the circuit controlling the energization of this electrode is clifierent from that previously described.

It is well known that when a capacitor is discharged through a spark gap, that discharge is of a generally oscillatory nature and may generally be considered to consist a train of damped waves. The frequency range of these oscillations is very broad, but it is possible to tune the circuit including the capacitor and the spark gap so that certain frequencies are favored over others. 'If this tuning is to a frequency where the energy level of the oscillatory discharge is normally relatively high, a relatively large oscillatory current will flow through the tuned circuit.

These characteristics of tuned circuits combined with capacitors and spark gaps make it conductor 83 to conductor 54; and the other terminal is connected by conductor 84 to one terminal 85 of a blocking capacitor 8B. 'The other terminal 8i of theblocking capacitor 86 is connected I by conductor88'to conductor 51, and thus a series circuit including primary winding -8| and capacitor 86 is connected in parallel with the gaseous conduction lamp 5'5.

A resistor 90 of relatively high resistance is connected in the circuit of capacitor 85 to act as a bleed for the latter andprevent its retaining a high voltage charge over a relatively 4 I long period of time; and a capacitor 9| may be connected in parallel with the primary winding 8| of transformer 80. The values of capacitor 9| and primary winding 8| are so chosen that the two cooperate to form a parallel-resonance circuit which is resonant at some frequency within the band produced bythe discharge of capacitor 30 through the spark gap formed by movable contact 44 and fixed contact 50 of-relay 45. Un-

8. der certain conditionsrthe=.capacitor 9| :mayrepresent :the distributed capacitance of the windings of the primary 8.1, while under other conditions it may. be :a small .mica capacitor connected across .the winding. .As .a result, when relay 45 is operated, .the resonant :features of the circuit including the capacitor 9| and primary 8| cooperate to produce a potential difference across the terminals of the latter which may be greater than the gpotential'difference appearing between conductors 54 and .51. Consequently, the secondary winding .82, which is constructed so that it normally has induced in it .a, voltage several times greater than that appearingacross the terminals of primary winding 8|, has a voltage appearing across its terminals which is many times that appearing between conductors 54 and 51. One of the terminals of thesecondary winding is connected by conductor 9.2- .to the trigger electrode 59, and :Lhavefoundthat most satisfactory results are obtained if the remaining terminal is connected byconductor as to conductor 83 This assumes that the transformer is wound so that, consideringinstantaneous polarities, when the terminal of the primary winding 81 which is connected-to conductor 83 is negative, the induced voltage in the secondary winding 82 is such that the polarityof the terminal connected to conductor .93 is also negative. The reason for the improved operation with these connections is not clearlyunderstood, 'but'Iihave found that definitely better .resultsare obtained from them than when conductor '93 is connected to conductor 85. These instantaneous polarities are indicated on the drawing.

'I have found that transformer. 3.0 may conveniently be formed by winding approximately 33 turns, spaced to cover about 1%" on a coil form approximately A in diameter, to form the primary winding .8], and by winding approximately 1 /2" of number .38 Formax enameled wire, closely wound, on the same coil form toform the second winding 82. With this transformer, I prefer to use a'capacitor 9| having a capacity of .003 mfd., though the value may'range between .001 to .02 mid, if desired. Similarly, the capacity of capacitor 86 may-varyxfrom ;0005-to .01 mfd., with a preferred value of .006 mfd., when used with ia resistor 90 havinga range of .25 to 4. inegonms, with a preferred value of .5 megohm. It is to be understood, of course, that the :values given above are given by way of illustration only, and not by way of limitation.

It will be seen from the fact that transformer 80 has an air core, that it is contemplated that the resonant frequency circuit including the primary Winding 8| and the capacitor 15 may he in the radio frequency range. Under suchconditions, the characteristics of .the conductor 50 and the-conductor 5? may become an important factor in the determination :of the various constants of the elements of thecircui-t. :Since the conductors 54 and .57 will usually be grouped together in a cable which may have a considerablev leng-th,it will be-seenthat these conductors act as a transmission line to the circuit. The impedance characteristics ,of such cables will vary widely, but I have found that by-making a suitable choice of the elements connected between conductors 83 and 88, yery satisfactory results may be obtained. The power requirements .of these various elements are verysrn-all, and 1 form ionizing controls which include the transformer 80, the capacitors Stand 86, and resistor .90 in a small unit approximately 19/ long ll d Operation of Fig. 2

When capacitor 3!] has been charged, and it is desired to discharge it through the lamp 56,

coil 46 of relay 45 is energized, thereby moving movable contact 44 from fixed contact 41 to fixed contact 50. A spark will occur between movable contact 44 and fixed contact 50, the contacts acting as a spark gap to create the oscillatory discharge of capacitor 30 in the manner previously described. At substantially the same time that the oscillatory discharge is taking place, the unidirectional voltage appearing between terminals 40 and 4! of capacitor 35 is impressed across conductors 5A and 51, thereby providing a direct current transient followed by substantially constant voltage. The steadystate components are prevented from reaching the resonant circuit by the capacitor $6, but the oscillatory and surge components are transmitted through the capacitor to the primary circuit where they induce greater voltage in the secondary 82 of transformer 80. This high potential is applied to the trigger electrode 59, thereby ionizing the gas within the lamp 56 and permitting the capacitor 30 to discharge between terminals 55 and 58 of the lamp to produce the brilliant flash desired.

It will thus be seen that I have provided an ionizing device for gaseous conduction lamps wherein the ionizing voltage is provided by a surge, whether a unidirectional impulse or an oscillatory surge, which is always present in the operation of such lamps, but which is of no benefit in their operation. Furthermore, it will be seen that the ionizing system I employ does not produce any continuous drain of the capacitor 3!! which operates the discharge lamp, since only the surge and not the steady state conditions are used in the ionizing system. Furthermore, the number of conductors which must lead from the power supply and control device to the lamp itself have been reduced from three to two, with a consequent savin in material and cost, and permitting the use of a smaller, more .inconspicuous cable. In addition, the conductors to the lamp are normally deenergized, and are energized only when the lamp is to be operated, thereby providing a much safer device.

While I have shown and described two forms of my invention, it is apparent that modifications may be made therein which in no way depart from the spirit of the invention as disclosed herein; and I do not wish to be limited to the particular form or arrangement of parts herein described and shown, except as covered by my claims.

Iclaim:

1. An ionizing system for a gaseous conduction lamp having discharge electrodes and a trigger electrode, the system including: a pair of conductors for connection to the discharge electrodes of the lamp; means for connecting said conductors, to a capacitor to produce an electrical surge in said conductors and to transmit the charge on said capacitor to the discharge electrodes of the lamp; and means connected to said conductors to receive th surge therefrom, said last mentioned means including a transformer having a secondary winding for connection to the trigger electrode of the lamp for applying a high voltage thereto to cause the operation of the lamp.

2. An ionizing system for a gaseous conduction lamp having discharge electrodes .and a trigger electrode, the system including:. a pair of conductors or connection to the discharge electrodes of the lamp; meansfor connecting said conductors to a capacitor to produce an electrical surge in said conductors and to transmit the charge on said capacitor to the discharge electrodes of the lamp; a transformer having a secondary winding connection to thetrigger electrode of the lamp; and means connecting the primary winding of said transformer to said conductors, said last mentioned means including means to transmit said surge to said primary winding but to prevent the steady-state condition of said conductor from being transmitted to said primary winding, whereby said surge causes a triggering voltage to be applied to the trigger electrode of the lamp.

3. An ionizing system for a gaseous conduction lamp having discharge electrodes and a trigger electrode, the system including: a pair of conductors for connection to the discharge electrodes of the lamp; means for connecting said conductors to a capacitor to transmit the charge on said capacitor to the discharge electrodes, of the lamp; and a transformer having a primary connected to said conductor and a secondary winding for connection to the trigger electrode of the lamp, whereby a high voltage is induced in said secondary and applied to the trigger erectrode of the lamp when said capacitor is connected to said conductors.

4. An ionizing system for a gaseous conduction lamp having discharge electrodes and a trigger electrode, the system including: a pair of conductors for connection to the discharge electrodes of the lamp; means for connecting said conductors to a first capacitor, whereby the charge on said first capacitor is transmitted to the discharge electrodes of the lamp; a second capacitor; and a transformer having a primary connected in series with said second capacitor to said conductors and a secondary for connection to the trigger electrode of the lamp, whereby a high voltage is induced in said secondary and applied to the trigger electrode of the lamp when said first capacitor is connected to said conductors, and the steady-state voltage of said conductors is not transmitted to said primary.

5. An ionizing system for a gaseous conduction lamp having discharge electrodes and a trigger electrode, the system including: a pair of conductors for connection to the discharge electrodes of the lamp; means for connecting said conductors to a capacitor, whereby an electrical surge is produced in said conductors and the charge on said capacitor is transmitted to the discharge electrodes of the lamp; a blocking capacitor; and a transformer having a primary winding connected in series with said blocking capacitor to said conductors whereby said surge is transmitted to said primary winding but the steady-state condition of said conductors is not transmitted thereto, and said transformer having a secondary winding for connection to the trigger electrode of the lamp, whereby said surge causes a high 11' voltage to be impressed upon the trigger electrode to ionize the gaseous discharge lamp.

6. An ionizing system for a gaseous conduction lamp having discharge electrodes and a trigger electrode, the system including: a pair of conductors for connection to the discharge electrodes of the lamp; means for connecting said conductors to a first capacitor, whereby an electrical surge is produced in said conductors and the charge on said first capacitor is transmitted to,

the discharge electrodes of the lamp; a second capacitor; and a transformer having a primary and a secondary winding, said primary winding being connected in parallel with said second capacitor and to said conductors whereby a resonant circuit is established in which said surge may cause a higher voltage to appear across the terminals of said primary winding, said secondary winding being connectable to the trigger electrode of the lamp to cause a high potential to r be impressed upon the trigger electrode to ionize the lamp.

7. A system as described in claim 6 in which a blocking capacitor is connected in series with said resonant circuit, whereby said surge is transmitted to said resonant circuit, but the steadystate voltage of said conductors is not transmitted thereto.

8. An ionizing system for a gaseous conduction lamp having discharge electrodes and a trigger electrode, the system including: a pair of conductors for connection to the discharge electrodes of the lamp; means for connecting said conductors to a capacitor, whereby an oscillatory electrical surge is produced in said conductors and a the charge onsaid capacitor is transmitted to the discharge electrodes of the lamp; a blocking capacitor; a bleeder resistor connected in parallel with said blocking capacitor to form a surge discriminating circuit adapted to transmit said surge but to prevent the transmission of the steadystate voltage appearing between said conductors; a transformer having a primary winding and a secondary winding, one terminal of said secondary winding being connectable to the trigger electrode of the lamp to impress a high voltage thereon, the remaining terminal of said secondary winding being connected to the terminalof said primary winding having the same instantaneous polarity; and a resonating capacitor connecting in parallel withsaid primary winding of said transformer to form a resonant circuit therewith, said resonant circuit and said surge dis criminating circuit being connected in series with each other and to said conductors, whereby the oscillations of said surge cause a high voltage to ionize the gas in the-lamp.

9. An ionizing system for a gaseous conduction lamp having discharge electrodes and a trigger electrode, the system including: a pair of condoctors adapted to be connected to the discharge electrodes: of the lamp; means adapted to connect said conductors to a capacitor, whereby an electrical impulse is produced in said conductors and the charge on the capacitor is transmitted to said discharge electrodes; a blocking capacitor adapted to transmit said impulse but to prevent the transmission of the steady-state voltage appearing between said conductors; and a transformer having a. primary and a secondary winding, one terminal of said secondary winding being adapted to be connected to the trigger electrode of the lamp to impress a high voltage thereon, the remaining terminal of said secondary winding and to be applied to the trigger electrode of the lamp one terminal of said primary winding being connected to one of said conductors, and the remaining terminal of said primary winding being connected in series with said blocking capacitor to the other of said conductors, whereby said impulse causes a high voltage to be applied to the trigger electrode of the lamp to ionize the gas in said lamp.

10. A system for ionizing and lighting a gaseous conduction lamp having discharge electrodes and a trigger electrode and requiring ionization in addition to any provided by the application of a normal discharge voltage to said discharge electrodes, the system including: a transformer adapted to be connected to a source of alternating current; a rectifier connected to said transformer to furnish a high voltage, unidirectional current; a multiple contact separable connector; a resistor connected in series between one terminal of said rectifier and a first contact of a first half of said connector; switching means having a movable contact adapted to selectively bear against either of two fixed contacts; a capacitor between a second contact of said first half of said connector and said movable contact of said switching means, one of said fixed contacts being connected to the remaining terminal of said rectifier, and the other of said fixed contacts being connected to a third contact of said first half of said connector; afirst, second, and third contact in the second half of saidconnector, corresponding to said first, second, and third contacts of said first half; means connecting said first and second contacts of said second half together, whereby said capacitor may be charged when said first and second halves of said connector are operatively associated together and said movable contact of said switching means bears against said fixed contact connected to said rectifier; a voltage divider connected in parallel with said capacitor; a glow lamp; a second capacitor; a resistor connected in parallel with said second capacitor, said resistor capacitance circuit being connected in series with said glow lamp between one terminal of the latter and a low voltage terminal of said voltage divider, the other terminal of said glow lamp being connected to another low voltage terminal of said voltage divider, said voltage divider being adapted. to provide a voltage substantially equal to the striking voltage of said glow lamp when said first capacitor is charged to a predetermined value, whereby said low lamp functions as part of an oscillator circuit and intermittently flashes when said first capacitor has reached a predetermined charge; means adapted to connect said third contact and said first and second contacts of said second half of said separable connector to the discharge electrodes of the gaseous conduction lamp; a transformer; means connecting the primary of. said transformer to said connecting means and means adapted to connect the secondary of said transformer to the trigger electrode of the lamp, whereby the moving of said movable contact to said fixed contact connected to said separable connector applies the charge of said first capacitor to the discharge electrodes of the lamp, and the impulse created thereby energizes said last mentioned transformer to supply an ionizing potential to the trigger electrode of the lamp. I

11. A system for ionizing and lighting a gaseous conduction lamp having discharge electrodes and a trigger electrode and requiring ionization in addition to any provided by the application of a normal discharge voltage to saiddischarge electrode, the system including: a capacitor; means adapted to charge said capacitor; a pair of conductors; switching means adapted to selectively connect said capacitor to said charging means or to said conductors; a voltage divider connected in parallel with said capacitor and having a pair of low voltage terminals; a glow lamp having one terminal thereof connected to one of said low voltage terminals; a second capacitor having one terminal connected to the remaining terminal of said glow lamp and the other terminal connected to the remaining low voltage terminal; a resistor connected in parallel with said second capacitor, whereby said glow lamp is caused to flash intermittently when said first capacitor reaches a predetermined charge; means for connecting said pair of conductors to the discharge terminals of the gaseous conduction lamp; a transformer; means connecting the primary of said transformer to said pair of conductors; and means adapted to connect the secondary of said transformer to the trigger electrode of the lamp, whereby the connecting of said first capacitor to said conductors applies the charge of said first capacitor to the discharge electrodes of the lamp and the impulse created thereby energizes said transformer to supply an ionizing potential to the trigger electrode of the lamp.

12. A flash-producing electric system including in combination a normally non-conducting gas discharge tube, a source of voltage having a potential less than the break-down potential of said tube, circuit-making means to apply said voltage across said tube, an electric-field-producing electrode in proximity to said tube, a pulse transformer having a step-up ratio, the primary of said transformer being connected in series with a condenser and the voltage across said tube,

means connecting the secondary of said transformer across one end of said tube and said electrode whereby the voltage pulse produced in said secondary in response to the application of said voltage across said tube causes the tube to break down to permit the discharge of said voltage through the tube to produce a flash.

13. A flash-producing electric system including in combination a normally non-conducting gas discharge tube, a condenser, means to charge said condenser to a potential less than the breakdown potential of said tube, circuit-making means to apply the potential of the charged condenser across said tube, an electric-field-producing electrode in proximity to said tube, a pulse transformer having a step-up ratio, the primary of said transformer being connected in series with a condenser and the applied potential across said tube, means connecting the secondary of said transformer across one end of said tube and said electrode whereby the voltage pulse produced in said secondary in response to the application of said potential across said tube causes the tube to break down to permit the discharge of the condenser through said tube to produce a flash.

ROBERT C. BECK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 22,611 Edgerton Mar. 6, 1945 1,937,389 Langer Nov. 28, 1933 2,140,840 Langer Dec, 20, 1938 2,341,541 Grier Feb. 15, 1944 2,342,257 Edgerton Feb. 22, 1944 Certificate of Correction Patent No. 2,513,396 RoBEgT o. BECK July 4,

It is hereby certified that error apiiears in the printed specification of the above numbered patent requiring correction as follows:

Column 10, line 1-2, for the Word or after conductors read for;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 10th day of October, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

